No trains are running between Manchester Piccadilly and Sheffield after a train derailed.
Major disruption is expected on services through Sheffield until the end of the day, National Rail Enquiries warn.
A freight train derailed just north of Sheffield, resulting in all lines through the South Yorkshire city being blocked.
Transport for Greater Manchester tweeted about the incident, saying: "Due to a derailment at Sheffield there are no rail services between Manchester Piccadilly and Sheffield in both directions.
"Road replacement transport is in place. Journey times will be longer."
Train operator Northern said the advice to passengers planning journeys from Sheffield is 'do not travel'.
This is due to 'the lack of road transport available and the number of routes affected', they warned.
